1. Field of the Invention
Subceilings formed from square or rectangular panels resting on the top surfaces of horizontally disposed flanges of inverted T-bar rails are well known. Typically, a framework of rails is formed with parallel main runners, suspended from the ceiling above, intersecting with cross rails to provide a grid pattern, usually as 2 feet.times.2 feet squares or 2 feet.times.4 feet rectangles, to accommodate similarly-sized subceiling panels. In its basic functional form, the subceilings would have the bottom surfaces of the rail flanges exposed as flat boundary strips between the edge supported panels.
For what has become the conventionally styled and dimensionally standardized version of the inverted T-bar rail, the industry has developed tight-fitting capping elements. By cutting and removing a portion of the panel along its length- and width-extending bottom edges to accommodate the thickness of the capped T-bar rails, a substantially smooth flat bottom surface of the subceiling may be defined.
It has been an objective to provide the option of various architecturally-satisfying decorative effects in suspended ceilings that have exposed flat T-bar flanges in addition to the mere capping discussed in the previous paragraph. It has also been an objective to provide such decorative effects with elements that are designed to be easily added in place or easily removed and replaced to satisfy the customer's "addiction" to his or her "remodeling habit".
2. Description of the Prior Art
In U.S. Pat. No. 4,848,054, the patentee has provided a hollow beam that is readily ,attachable from below onto the bottom flanges of the T-bar rails of the conventional T-bar support without requiring additional fastening hardware or tools. The beams are supported by return flanges at the top of their vertical sidewalls, resting on the top sides of the flanges of the T-bar rail. The beams may be reinforced by a transverse web bridging the top region of the sidewalls. A longitudinal groove is provided along the upper portion of each vertical sidewall. The inward intrusions of the grooves, in co-operation with the bridge web when used, function as a strike plate against the bottom side of the rail flanges to constrain the beam from skewing or working upwards.
To accommodate clearance at the intersections of the inverted T-bar rails that function as main runner members and cross runner members, notches must be provided in the beams. However, as shown in FIG. 7 of U.S. Pat. No. 4,848,054, this system provides a discontinuous appearance when viewed from below.
It is a similar object of the present invention to provide beams for capping the inverted T-bar support rails used in conventional support systems for subceilings that are readily attachable and removable from below without using any additional fastening hardware.
It is a further object of the present invention to provide a beam that is, once in place, constrained from undesired movement such as skewing or riding upwardly on the rail flanges.
It is a still further object to provide an element that is simpler and less expensive than the hollow beams with vertical sidewalls of the prior art and displays a substantially greater amount of versatility and ease of installation, particularly in providing a novel and a more integrated appearance at the intersections of the runners than the hollow beams of the prior art.